This is an archive of all the messages from the Stella Programming
Mailing List. This is currently one of the best places to discuss
2600 programming and the archive contains a lot a good information
and source code.

This tutorial explains two easy methods that may
be used to change the graphics in an Atari 2600 / VS game.
A step-by-step example is provided that gives the details on how
to change the graphics in "Space Invaders." No programming
experience is required to follow these instructions.

Development Software

DASM.ZIP: This is an excellent 6502
cross assembler for MSDOS. It supports pretty much any feature you
could want in an assembler including macros, and the ability to
produce raw-binary files. Thanks to Bob Colbert for porting this
assembler from the Amiga.

2600gfx.zip: These programs allow
you to extract graphics from Atari 2600 binary files into a text
file, then turn the text file back into a binary. You can use these
programs to put your own graphics into 2600 games.

distella.zip: This is an excellent
Atari 2600 cartridge disassembler. I creates re-assembleable code,
puts in register labels, and automatically separates data from code.

Emulators

One of the easiest ways of doing 2600 development is to simply
run you code on an emulator. There are a number of emulators currently
available for MSDOS, Windows, and other platforms. For development
work I recommend PC Atari by John Dullea.

Virtual VCS is an MSDOS port of the x2600 VCS emulator (later
now known as Virtual 2600) which was written by Alex Hornby. This
was the first emulation project I worked on and I was quite proud
of the results. I have stopped further development on it since it
has been superceeded by other much better 2600 emulators, and because
I have moved onto other projects. I am leaving the source and binary
here for educational purposes.

Virtual VCS and x2600 are distributed under the terms of the
GNU Public Licence.

NOTE:

Due to the flood of good Atari 2600 emulators in the past few
months I will not be doing any future development on VVCS. I am
very glad to have provided the first non-commercial Atari 2600 emulator
for MSDOS and to have given a boost to some of the later 2600 authors,
who's emulators are now superior to mine.

Schematics

The following are schematics that I have traced out by hand.
I cannot guarantee that these schematics are accurate, or that
they are the same for all versions of a piece of equipment.
These where all draw with Orcad, exported to a DXF file, imported
into Corel Photopaint, then exported as a GIF.